The bq24640 charges a super capacitor in two phases: constant current and constant voltage (CC/CV). The device can charge super capacitors from 0 V with current set on the ISET pin. When the super capacitor voltage reaches the programmed target voltage, charge current begins tapering down.

The bq24640 has an input CE pin to enable and disable charge, and the STAT and PG output pins report charge and adapter status. The TS pin on the bq24640 monitors the temperature of the capacitor and suspends charge during hot and cold conditions.